Fetal MRI of clubfoot associated with myelomeningocele

The sensitivity and specificity of evaluating clubfoot deformity by MR in high-risk fetuses is currently unknown. To correlate fetal MRI with US in the assessment of clubfoot and to identify the MRI features most characteristic of clubfoot. With IRB approval and informed consent, the presence of fetal clubfoot was prospectively evaluated in mothers referred for MRI for a fetus with myelomeningocele. Two radiologists blind to the US results independently reviewed the MRI for the presence of clubfoot. MRI results were compared with US results obtained the same day and birth outcomes. Of 20 patients enrolled, there were 13 clubfeet. Interobserver agreement for the presence of clubfoot was 100%. The sensitivity of the MRI exam was 100% and the specificity 85.2%. A dedicated sagittal imaging plane through the ankle region allowed the most confident diagnosis; medial deviation of the foot relative to the leg was seen in all 13 fetuses with clubfoot. The correlation of fetal MRI with US in the evaluation of clubfoot yields a sensitivity of 100% and specificity of 85.2%. The sagittal plane provided the most useful information. (orig.)